Door operating mechanism



July 12, 1960 D. R. STUETTIG ETAL 2,944,810

DOOR OPERATING MECHANISM Filed Aug. 21, 1958 4 Sheets$heet 1 7i nzt-///drnegg y 1960 D. R. STUETTIG ETAL 2,944,810

DOOR OPERATING MECHANISM Filed Aug. 21, 1958 4 Sheets-Shet 2 July 12,1960 DR. STUETTIG E'rAL 2,944,810

DOOR OPERATING MECHANISM Filed Aug. 21, 1958 4 Sheets-Sheet 3 y 12, 1960D. R. STUETTIG ETAL 2,944,810

DOOR OPERATING MECHANISM 4 Sheets-Sheet 4 Filed Aug. 21, 1958 lllll NQNr! ll 7 5 1 WM 2 m N/ 06 f MWM r71 K wr m \J NM United States Patent73cc DOOR OPERATING MECHANISM David R. Stuettig, Manhattan Beach, VirgilD. Jones, Inglewood, and Richard G. Golding, Lawndale, Cahf., assignorsto Zeta Electronics, Lawndale, Calif.

Filed Aug. 21, 1958, Ser. No. 756,445

5 Claims. (Cl. 268-59) The present invention relates to electricallyactuated mechanisms for operating garage doors and the likeautomatically, either in response to an actuating signalradiated from anautomobile or upon the closure of an electric switch situated, forexample, in the garage or in the house associated with the garage.

The mechanism of the invention probably finds its greatest utility inconjunction with garage doors for automatically opening and closing suchdoors upon the receipt of appropriate radiated signals, or upon theactuation of control switches. For that reason, the improved mechanismof the invention will be described in such an environment. It willbecome apparent as the description proceeds, however, that the improvedmechanism of the invention will find utility in any application in whichthe opening and closing of a closure member is to be electricallycontrolled.

.The most important requirement of the garage door operating mechanismsis, of course, that they be absolutely safe in their operation andincapable of injuring any person using the mechanism or in the vicinityof the door as it is opened or closed, or of damaging any property thatmight be in the way of the door as it is automatically opened or closed.

The dooroperating mechanism of the present invention completely fulfillsthe safety requirement outlined in the preceding paragraph. Themechanism of the invention includes a positive means for immediatelyarresting the opening or closing motion of the door by the mechanismshould the door engage any object tending to impede its opening orclosing motion. Therefore, when the mechanism has been actuated to closethe door, for example, and should a motor vehicle or other object beinadvertently left in the path of'the closing door, or should a child orother person come into the path of the closing door, immediately uponthe contact of the door with the object or person, its downward motionis positively stopped. This also applies to anything or anyone impedingthe upward motion of the door, when the mechanism of the invention hasbeen actuated to open the door.

A further safety feature of the embodiment of the door operatingmechanism of the invention to be described is the provision of asecondary switching mechanism which preserves the downward safety stopfeature of the door operating mechanism of the invention despite failureof the control mechanism such as switch failure or relay failure. Normaloperation of the door operating mechanism may be restored after thesecondary switching mechanism has been actuated only after themalfunction causing primary control circuitry failure has been locatedand repaired, thus affording an important self-check feature.

Another feature of the improved door operating mechanism of theinvention is its high degree of reliability and its capabilities for along and trouble-free life. This is achieved by the avoidance ofcomplexity in the'construction of the mechanism and by the avoidance ofany extraneous components. Reliability is also achieved by theassignment of the necessary functions of the equipment to a minimum ofparts which in themselves are rugged in their composition and extremelysimple in their operation.

A belt drive is used, for example, between the electric motor whichdrives the mechanism and the driven shaft pulley in the embodiment ofthe invention to be described. The flexibility of the belt drive permitsaxial misalignments between the motor pulley and the driven shaft pulleywithout loss of torque, and without creating undue wear.

The belt drive arrangement, referred to above, is extremelyadvantageous, moreover, for the type of loads exerted on the mechanicaldriving mechanism in the control of a garage door. Such loads are highlyinertial and sub ject to sudden variations. The use of gears for thesame purpose would be impractical, because of the size and strengthrequirements for such gears to be capable of properly performing underthe peculiar load conditions with which the mechanism of the inventionis intended to operate.

The door operating mechanism of the invention is also economical andreliable in its electric control circuit, this circuit is extremelysimple in its design and straightforward in the composition of itscircuitry and associated components. In the embodiment to be described,for example, two relays of known construction are used, and only one ofthese actually switches motor current. The other is the reversing relay,and it carries motor current. However, the latter relay is timed so thatit does not switch motor current, rather, it changes its contacts fromone operating condition to the other when no current is flowing throughthe motor. This means that high switching current contact requirementsneed be met only in one of the two relays which actually control theoperation of the mechanism.

The increased reliability of the door operating mechanism of theinvention as compared with the prior art mechanisms of this general typeresults in longer life of the unit and decreased maintenance costs. Alsothe likelihood is minimized of access to the motor vehicle in the garagebeing obstructed due to failure of the mechanism. To render it virtuallyimpossible under any circumstances, even if power failure occurs, forthe door operating mechanism to actually obstruct access to the motorvehicle in the garage, the embodiment to be described in-- actuated.This enables the garage door to be opened manually when the situationrequires it.

The door operating mechanism of the invention also has the advantage ofbeing relatively small in size and relatively easy to install. Aboutpercent of the weight of the mechanism may be concentrated, for example,in a housing which supports the drive motor and other drive elements ofthe assembly. This housing is relatively compact in size, and it isintended to be mounted on the door header portion of the door frame ofthe garage to be directly over the center of the garage door when thedoor is closed. This is clearly an ideal position for the unit since iteliminates the need for additional bracing to take up the weight and thethrust forces, such additional bracing being almost universally requiredby the prior art units.

The above and other features and advantages of the door operatingmechanism of the invention will become apparent from a consideration ofthe following descriptive material in conjunction with the accompanyingdrawings in which:

Figure 1 is a perspective view of the improved door operating mechanismof the invention illustrating the mechanism mounted in place over agarage door, this view showing the drive motor and its associatedhousing mounted on the header of the door directly over the center ofthe door, and including a lead screw which extends back from the planeof the door in its closed condition to be rotatably supported at its.remote end from a rafter of .the garage, and this view showing a nutmeans which rides on the lead screw and. W-hichin this particular viewis disposed toward the leading end of the screw, with thenut means beingcoupled by a pivoted linkage to the top of the door;

Figure 2 is a view substantially on the line 2--2 of Figure 1 to showfurther details of the means at the remote end of the lead screw forrotatably supporting the lead screw from the rafter of the garage;

Figure 3 is a view similar to the view of Figure l but showing the nutmeans disposed toward the rear end of the lead screw and the garage doorin an open condition;

Figure. 4 is a top view of the drive motor and associated housingportion of the door operating mechanism of the illustrated embodiment ofthe invention, with the toprbeing removed from the housing to reveal itsinternal components;

Figure 5. is a sectional view substantially on the line 5-5 of Figure 4to show the manner in which the drive motor is coupled to a pulleymounted on a driven shaft, the driven shaft being coupled to the leadscrew and in essentially axial alignment with the lead screw;

Figure 6 is a fragmentary view showing the linkage means which couplesthe mechanism to the garage door and which is pivoted to the top of thegarage door and to a nut means which rides on the lead screw describedabove, the particular nut means illustrated in Figure 6- door, the meansof Figure 7 including a releasing mechanism' for releasing the dooroperating mechanism from the garage door, when so desired; and

Figure 8 is a circuit diagram of a suitable electric control for themechanism illustrated in the other figures.

As shown particularly in Figures 1, 2 and 3, the improved assembly ofthe invention includes a housing it) which contains the various drivecomponents of the assembly, as will be described, and which alsocontains the drive shaft and pulley of a motor 12 which is mounted onthe housing. The housing is adapted to be mounted on the header 14 ofthe doorway of a garage, for example, and it is adapted to be positioneddirectly over the center of the plane of the garage door 16 when thedoor is in a closed position. Asshown in Figures 1 and 3, the housingmay be appropriately mounted on the header 14 by a pair of brackets 18which are screwed into the header by means of screws such as the screws20, the housing being fixed to the brackets 18 in any appropriatemanner.

A driven shaft 22 extends out of the housing 10 directly over the motor12, as shown in Figures 1 and 3. The drive shaft of the motor 12 iscoupled to the driven shaft 22 in a manner to be explained in detailsubsequently. The driven shaft 22 is coupled to an externally threadedelongated rod member, such as a lead screw 24 by means of a suitableresilient universal coupling 26. The resilient universal coupling 26allows the lead screw 24 to be positioned at a small angle from thehorizontal. The lead screw 24 may be one inch in diameter, and it mayhave four threads to the inch. The lead screw may be composed of steelor aluminum, for example, and it may have a typical length of 72 inches.As shown in Figure 5, the coupling 26 may include a medium hard rubberdamper 27 having a typical dimension of .75 inch diameter by 1 inchlength.

The end of the lead screw 24 remote from the housing 10 may be machinedto a diameter of, for example, .625 inch. This machined end section isdesignated as 24a in Figures 1 and 2, and it may have a length of, forexample, four inches. A stop collar 28 is mounted on the end of the leadscrew 24 adjacent its end section 24a. This collar is bolted to the leadscrew by a bolt 30 which extends through the collar and. through thehead screw, this bolt assuring a rigid, stable mounting for the collaron the lead screw. The collar 28 forms a limiting stopfor a movablerecirculating ball bearing nut 32 which is threaded to the lead screw,and which is adapted to move reciprocally and rectilinearly with respectto the longitudinal axis of the lead screw as the lead screw is rotated.

A washer 34 is mounted to the extreme end of the lead screw 24 by means,for example,.of a bolt 36 which is threaded into the end of the leadscrew. The remote end of the lead screw is rotatably suspended from arafter 40 of the garage by means of a rear hanger. or sling assembly 42(Figure 2). This rear hanger includes, for example, a bearing member 44which is best shownv in Figure 2 and which includes a tubular nyloninsert 46. The bearing member 44 is suspended. by means of a pair ofscrew rods 48, the screw rods extending into a mounting plate 5i) whichis threaded to receive the rods and which provides for a rigid mountingfor the. rear hanger.

The machined end portion 24a of the. lead screw 24 extends through thenylon insert of the bearing member 44 in rotatable relationship with thehearing. Therefore, the remote end of the lead screw 24a is. supportedfrom the rafter without impairing the ability of the lead screw to berotated. :It should be noted at this point. that the bulk of the weightof the door operating mechanism is supported in the housing 10, which,in turn, is rigidly mounted on the header 14 of the garage. This.precludes. any necessity for extra bracing, as is usually required whenthe actual operating mechanism is supported back in the vicinity of therear hanger 42.

The electrical controls for the door operating mechanism are housed in ahousing 52 (Figure 1). This housing is shown in Figure l as beingseparate from. the housing 10 and supported at the corner of the header14. However, it will become evident as the present description proceeds,that the electrical controls may 'alsobe incorporated in the housing 10to form a single unit. 7 A light 54 may be conveniently included in thehousing 52 or on the housing 10, and this light is controlled to be.energized whenever the mechanism is operated to open the door. Thisprovides an automatic illumination in the garage whenever the door isopen, and the light automatcially is turned off when the door is againclosed.

Details of the driving assembly for the mechanism. are shown in Figures4 and 5. This driving assembly, asnoted above, is housed in the housingIt}. The motor 12 is mounted at the bottom. of the housing 1.0, and thismotor may conveniently be a quarter-horsepower 1 725 rpm. induction typemotor. The motor has a driven shaft 60 which is mounted in the motorcasing inusual. motor bearings. The drive shaft 69 extends into thehousing 10 and a pulley 52 is mounted at the end of the drive shaft bymeans, for example, of a set screw 54-. The pulley 62 may be a usual 2%.inch V-type belt pulley. The driven shaft 22 is rotatably mounted in thehousing 10 in. spaced parallel relationship from the drive shaft 60. Thedriven shaft, for example, may be so mounted in the housing It) in apair of bearings 66 and 68 which. are mounted in the opposite walls ofthe housing. A pulley 76 is mounted on the driven shaft 22 in alignmentwith the pulley 62 The pulley 7h may, for example, be a 4 /2. inchaluminum pulley. The pulley 79 is affixed to the shaft by appropriateset screws such as the set screw72. A usual V-type drive belt 74-intercouples the drive-pulley 62 with the driven pulley 70. 7 l

e As shown in Figure 5, the section of the driven shaft 22 which extendsinto the housing has a reduced diameter with respect to the diameter ofthat shaft outside of the housing The section of'reduced diameter formsa shoulder 76 with the section of increased diameter. the bearings 66and 68, as mentioned above, however, this shaft is also capable of axialmovement in the bearings. A pair of thrust bushings 80 and 82 aremounted on opposite sides of the pulley 70 in coaxial relationship withthe driven shaft 22. A second pair of thrust bushings 84 and 86 aremounted on the inner sides of the respective bearings 66 and 68 incoaxial relationship with the driven shaft 22. These thrust bushings maybe composed of, for example, case hardened steel.

A pair of compression springs 88 and 90 of the coiled type are supportedrespectively on the bushings 80 and 84 and 82 and 86 in coaxialrelationship with the driven shaft 22. These springs are preferablynon-linearly wound, and each may have a length of 2.44 inches with anouter diameter of 1.14 inches. Eech may include eight coils of No. 6wire. These compression springs serve to bias the pulley '70 into axialalignment with the drive pulley 62. However, a sufiicient axial forceexerted on the shaft 22 is capable of overcoming the compression ofone'of the springs or the other to move the pulley 70 to the left or tothe right in Figures 4 and 5. The purpose of the bushings is to providebearing surfaces for the springs 88 and 90. Spring bearing surfaces arenecessary to reduce rotational friction between the springs and thepulley 70 and the housing 10. Pulley displacement is limited duringcompression of the springs 88 and 90 in either direction by the contactof opposite bushing surfaces, as, for example, the meeting of bushings80 and 84, or 82 and 86.

As noted above, the universal coupling 26 is shown in somewhat moredetail in Figures 4 and 5. This coupling serves to couple the lead screw24 to the driven shaft 22, and the coupling serves to permit such acoupling with the lead screw being disposed at an angle tothe drivenshaft 22. This angle, is preferably of the order of 8 to 12 degrees forthe ,swing-up type of garage doors, and from -2 to +2 degrees for theroll-up type of doors. The coupling 26 is composed of a rubber centralbody 29 which includes the damper 27 referred to above. It also includesannular collars 3'1 and 35 which are secured to the lead screw 24 and tothe driven shaft 22 by means of a plurality of set screws, such as theset screws 33 in Figure 4.

It is clear then that when the motor 12 is energized, the resultingtorque exerted on the pulley 62 causes the pulley 70 and the drivenshaft 22 to rotate. This causes the lead screw 24 to rotate at theselected angle to the driven shaft 22. 1

As shown in Figure l, a linkage 92 is pivotally attached to the nut 32at one end and in a mannerto be described, and is pivotally mounted tothe upper edge of the garage door 16 at its other end in a manner alsoto described. This linkage couples the ball bearing nut 32 to thebracket assembly 114- attached to the top of the door 16. The resilientuniversal coupling 26 assists the linkage 92 in exerting forcecomponents for the ,operation of the usual swing-up type of overheadgarage door, as will be described in more detail subsequently. Theroll-up type of garage door does not require the disposition of the leadscrew 24 at an angle. However, the universal coupling may also be usedfor the latter type of door to facilitate the coupling of the lead screw24 with the driven shaft 22 This arrangement is such that when the motor12 is driven in one direction, the lead screw rotates in a particulardirection to cause the nut 32 to move back toward therear end of thelead screw to open the garage door. Then, when the direction of drive ofthe motor 12 is reversed, the nut 32 is'cau'sed to ride along the leadscrew toward its forward end to close the garage door. 7

The driven shaft 22 is rotatably mounted in The geometry of the linkage92 is specifically designed advantageously to lift and close the door ina manner which exerts virtually no lateral or vertical force momentsupon the axis of the lead screw 24. This specific design is importantfor the operation of swing-up doors. Swing up doors of this type do notdescribe an arc corresponding to a segment of the circumference of asingle circle. Rather, the locus of points describing the path taken bythe top of the door consists of two arcs, approximating segments of twointersecting circles of different radii.

Considering the movement of a swing-up door in the upward direction, anarc of relatively large radius is described during approximately thefirst 20 of rotation from the vertical. After the first 20, an abruptchange in the door path occurs, caused by the raising action of theassociated lever components This latter action results in the movementof the top of the door in approximately an arc of a circle of relativelysmall radius as compared with the arc of the radius for the first 20 ofrotation.

The second are described by the top of the door is described during therising phase of the door which occurs during the of rotation following.the initial 20. This second arc continues, although somewhat flattened,for the final 10 of rotation as the top of the door 16 is dropping. Themovement described above occurs as the door is moved from its closedcondition of Figure 1 to its open condition of Figure 3.

The movement of the nut 32 during the above described opening of thedoor is essentially horizontal and along the axis of the lead screw 24.For this reason, the linkage 92 is bent in a manner to resolve thetransverse movement imparted by the'nut into vector components which arein the proper directions to pull the top of the door tangentially, tothe circular arcs described by the top. Such tangential application ofthe force is neces sary to produce the required :vertical rotation ofthe door by the linkage 92 at the intersecting point of the two arcs.

The linkage 92 is also constructed with a configuration to provide thenecessary lift required. to raise the top of the door 16 when the dooris being pushed down from an up position, The lattersituation occurswhen it is desired to close thedoor by the reversed rotation of the leadscrew 24 and by the reversed travel of the nut 32.

The linkage 92 does not require a precisely designed configuration whenoperating doors of the roll?up" or. horizontal track type. 'Howeventhelinkage 92 with a configuration properfor the operation of the swing-up7 doors can also conveniently be used to operate these-latter types, andother types, of doors. Forces required to be coupled through the linkage92 to the top of the door 16 vary over a Wide range. Theseforces are amaximum at the limiting positions of door travel in the open and closedpositions. During door rotational motion from the open to the closed.position, or from the closed to the open position, these forces mayvary, for example, between 0 and 30 pounds.,,

Anincrease in" the optional force atthe top of the door 16 is created inthe event that an obstruction is met by the bottom of the door. Due tothe geometry of the lever mechanism associated with the swing-up'type ofdoor, a small force at the bottom of the door opposing door movementresults in a large force at the topof the door.

The force required'at the top of the door to produce rotational movementof the door is, therefore, increased as a result of the obstructionreferred to in the preceding paragraph. This increase in forcerequirements is translated through the linkage 92 to the nut 32 in anopposite direction to the axial movement of the nut 32. This reduces.the axial movementofthe'nut 32 on the lead screw .24 which causes. thelead screw to displace the driven shaft 22' axially,' the displacementforce to the driven shaft being transmitted through the coupling 26.This movement of the;r,otating lead screw24 with respect to the nut 32.produced when resistance: to movement ofithenut. is: introduced from thedoor to the nutthrough the. linkage .92". increased. resistance causesthe. nut 32 virtually" to stop. The continued rotationof the lead screwthencarries the. lead screw through the nut, axially to move theleadscrew so as to produce the above described displacernent to thedriven shaft 22;

The action described inthe preceding paragraphs causes the leadscrew 24to move axially against the ten sion of the springs 88 or 90inthehousing 10 in one direction or the other. The arrangement is suchthat when an increased door'load condition is met during the openingofthe door, the driven shaft- 22m'oves to the leftin Figures 4 and 5, andwhen the garage door load increases while it is being closed,theincreased force requirement causes the driven shaft 22 to move to theright in Figures 4 and. 5.

Asshown in Figure 4, for example, a pair of switches I- and 102 aremounted inside the housing on one side of the pulley 70, and a switch104 is mounted inside theheusing 10' on the other side of the pulley70.These switches may be of the'typecommonly designated microswitches. Eachof the switches has an actuating arm, which are designated respectivelyas 106, 108 and 109; and each arm has a roller at its outer extremity,the rollers being designated respectively as 111, 113 and 115. When thedriven shaft 22 is moved to the right in Figures 4 and 5, by the garagedoor load condition increasing as it is being closed, such movementcauses the pulley 70 to engage the roller 111 which, in turn, causes theactuating arm 106 to move down and actuate the switch 100. In likemanner, movement of the driven shaft 22 to the left in Figure 4, due toan increased load condition on the door asit is being opened, causesthepulley 70 to engage the roller .115 of the actuating arm 109 so as toactuate the switch 104.

The switches 100 and 104- are connected into a relay circuit whichinterrupts the currentapplied to the motor 12, and reverses thedirection of motor rotation. The relay circuit is to'be described inconjunction with Figure 8; By means of the relay circuit, the motor 12is driven until an obstruction is encountered by the door, or until thedoor reaches its limiting up position or its limiting down position. Forany of the latter conditions, the motor 12 is stopped, as is the up ordown movement of the door. Then when the motor is next energized, themotor rotation is reversed which causes thedoor to move in the oppositedirection to the direction it was moving when the obstruction orlimiting position wasreached.

A third rnicroswitch 102 is mounted on thesame side at the-housing 10'as the down direction load sensing microswitch 1'00; The-purpose of theswitch 102' is to protect the door operating mechanism of the invention,preserve the safety stop feature ofthe mechanism, and to indicatemalfunction intheevent of a failure in the relay circuit.

During normal running conditions, the microswitch 102 is not operatedbecause of its position in the housing 10. By placement and adjustment,the microswitch 102 is located in a manner which causes its roller 113to be behind the plane of-the-roller .111 of the down sensingmicroswitch 100. Consequently, under normal operation, the pulley 70engagesthe. roller 1 11 of the actuating arm 106 to actuate the switch100 and stop the motor 12', beforethe-pullcy 70 is shifted by the leadscrew 24 to a position in which it can engage-the roller 113' of theswitch 102.

Actuation of'the switch 102. causes a switching action tooccur in therelay circuit of Figure 8, as will be described in conjunction withFigure 8, and this switching action de-energizes' the motor 12regardless of. all other conditions of the relay circuit; Actuation ofthe switch 102 in the door downward limiting position renders allswitching circuits ineffective to initiate powered door movement untilthe lead screw Mia rotated manually.

8 This assures that the mechanism will be held-in an, ineffective.condition until an acknowledgement of the fault hasbeen made and thefault has been corrected.

The coupling between: the lead screw 24 and the nut 32'is such thatalthough rotation of the lead screw causes the nut to move rectilinearlywith respect to the lead screw,. the nut-itself isincapable of producingrotation of the: leadscrew. Therefore, whenever the motor 12 isde-energized, and regardless of the position of the nut 32 on. the headscrew, such de-energizing. of the motor causes the lead screw to beimmediately stopped and locked at that position. This precludes anypossibility of the garage door falling to a closed position, should theoperating mechanism. be de-energized while the door is partially orfully opened.

Locking of the nut 32 on the lead screw 24, with forces exerted at thebottom of the door being inelfective incausing rotation of the leadscrew also provides an important feature of the invention. That featureis the locking of the door securely against unauthorized entry to thegarage-when the door is in the down position. A manuallyoperated,lo'cked disconnect, to be described in conjunctionwith Figure'7is the only means of circumventing this locking action, apart fromenergizing the motor 12 through the c'ontrol circuit.

Further details of the linkage 92 and the Way in which it is pivotallymounted to the nut of the operatingmechanism. and" to thetop of thegarage door 16 is shown in- Figure 6. As shown in that figure, thelinkage has a pair of sections which. are disposed at an angle to oneanother. These sections may, for example, be 11.25 inches and 1 0.50inches long respectively, with the longer section being coupled to thenut assembly. Also, the angle between the's'ections may be of the orderof 50-56 degrees. A slightly modified nut means is illustrated in theshowing of Figure 6, thisnut means using a pair of ball nuts 32a and 32bmounted in back-to-back relationship and threaded into a threadedannular yoke 110. These ball nuts may be of a usual known type. The ballnuts use, for example, alternate ballsof nylon and steel, each having adiameter of of an inch.

The threaded annular yoke may be an aluminum casting, and it includes aclevis fitting 112 extending downwardly from its main body portion. Thebrackets of this clevis fitting are spaced in parallel relationship, andthey are adapted to receive the end of the linkage 92. Nylon isolationbushings may be inserted in holes located in each bracket of the clevisfitting 112, and a suitable bolt 113 may extend through the bracketsthrough the bushings and through the upper end of the linkage 92 topivotally support the linkage in the yoke 110. As in the previousembodiment, rotation of the lead screw 24 causes the nut means 32a, 32band the yoke 110 freely to move in a reciprocal manner with respect tothe lead screw. However, any'linear force on the yoke 110 is incapableofmoving the nut means along the lead screw, or of rotatin'gfltheleadscrew 24, when the drive motor is deenergiz'ed.

The other end of the linkage a2 is pivotally mounted in a bracket 114(Figures 6 and 7) which is supported on the top of the garage door 16 asan integral part of the disconnect mechanism referred to above. Thebracket 114 includes a pair of spaced parallel flanges 116 and 118, andthe lower'end of the linkage 92 extends through these flanges'to bepivotally supported on a pin 120. The pin 120 extends through theflanges 116 and 118, and through the end of the linkage 92. The pin isin the form of an eye-bolt, and it is extractable from the flange 118.Alspring 122 is secured to a cable 124 and to the flange 118, thecabl'ebeing fastened to the eye of the pin 120. The spring serves toresiliently hold the pin 12%? in place so that the lower end of thelinkage M may be pivotally connected to thebracket 114.

The. cable 124 extends over a pulley 126 which may be mounted on asuitable mount 128 which, in turn, is

9 V 7 supported on the base of the disconnect mechanism. The pulley 126is rotatably mounted on the mount 128 by a pin 130, and the cableextends down through a hole in the base of the disconnect mechanism anddown the inner side of the garage door 16. It is apparent, that whenevera sufiicient tension is placed on the cable 124 to overcome the tensionof the spring 122, that the pin 120 is withdrawn from the flange 118 sothat the linkage 92 is disengaged, and the door 16 may be manuallyopened. This serves as a conventient means for disconnecting themechanism from the garage door in the event of a power failure ormalfunction so that access to the motor vehicle will not be obstructed.The lower end of the-cable 124 is secured to a usual type of center lockoverhead garage door handle assembly 125. The lock handle assembly 125is key-operated from the outside of the door, and upon the operation ofthe lock by the proper key, sufficient tension is exerted on the cable124 by manually rotating the exterior handle of the assembly 125 towithdraw the pin 120 and to free the door from the door operatingmechanism.

When the door 16 is in the down position, the end of the linkage 92 iscaused to engage a jamb plate 119 which is mounted on the header 14. Thepurpose of this arrangement is to facilitate the disengagement of thelinkage 92 from the disconnect mechanism.

The jamb plate offers a resistance to the force exerted by the spring 90through the driven shaft 22, the lead screw 24- and the linkage 92 whenthe spring 90 is compressed when the door is in the downward limitingposition. The downward limiting position is in fact determined by thecontact of the pointed end of the linkage 92 and the header jamb plate119. This contact of the linkage 92 with the plate 119 relieves the pin120 from rereiving the jambing force created by the compression of thespring 90. This permits sufficient looseness of the pin 120 to enable itto be withdrawn with relative ease through the linkage 92 and from theflange 118.

In addition, the jambing of the linkage 92 into the jamb plate 119 holdsthe linkage in a constrained position independent of the door. Thisallows the door to be operated manually without interference by thelinkage 92. This arrangement also facilitates manual-door operation bymaintaining a fixed alignment between the linkage 92 and the disconnectassembly when the door is down to facilitate the insertion of the pin120 when powered operation is desired.

Suitable electrical circuitry for operating the door operating mechanismdescribed is shown in Figure 8. This circuitry includes a pair of inputterminals 200 which are adapted to be connected to a relay included inan electronic remote control unit 202, and which operates in response tothe proper radiated signal from a device included in the motor vehicle.Suitable electronic equipment is known which will respond to theradiated signal from the motor vehicle to close a pair of relay contactsin the unit 202, and it is believed unnecessary to describe such amechanism in detail in the present specification, since such mechanismforms no part of the present invention. The terminals 200 are connectedto a pair of leads 204 which are also connected to a pair of inputterminals 206. The latter input terminals connect with usual pushbuttonswitches, such as the switches 208 and 210. One of these switches may bepositioned in the house to permit the garage door to be automaticallyopened, for example, from inside the house. The other may be positionedin the garage to permit a similar control of the opening and closing ofthe door to be carried out inside the garage.

The unit also includes a pair of input terminals 212 which are adaptedto be connected to the usual 115 volt ,6!) cycle power line availablefor domestic use. An earth ground is provided by connection from thehousing 52 and 10 frames to the electrical conduit.

' The input terminals 212 are connected to the primary of a transformer.214 through a fuse 222. The secondary of the transformer is connected toa common lead 205 and to one of the leads 204. This lead is alsoconnected to a terminal designated 5 on a connecting block 216. Theother one of the leads 204 is connected through a 22 ohm resistor 207 toa normally open fixed'contact A of a relay 218. The contact A has anarmature B associated with it, and this armature is connected to aterminal 6 on the connector 216. The relay 218 is the primary controlrelay, and it also has a second normally open fixed contact C. Thissecond fixed contact is connected to a terminal designated 1 on theconnector 216. One terminal of the primary of the transformer 214 isconnected to the armature D of the relay 218 associated with thenormally open contact C. The other terminal of the primary of thetransformer 214 is connected to an armature F of a motor reversing relay220, and this latter terminal is also connected to the illuminating lamp54 (referred to previously) and to a terminal 2 of the connector 216.

The connector 216 has a terminal 10 which connects with one side of theenergizing winding of the relay 218, the other side of this windingbeing connected to the common lead 205. The connector 216 also has aterminal 9 which is connected to the switched side of the leads 204. Theconnector has a terminal 8 which is connected to an armature Bassociated with a normally open contact A of the motor reversing relay220. This latter contact A is connected to a terminal 7 of the connector216 and to one side of the energizing winding of the relay 220.

The lamp 54 is connected to a normally open contact C of the relay 220,and the armature D associated with that contact is connected to thearmature D of the relay 218. The connector 216 has a terminal 4 which isconnected to a normally open contact E of the relay 220 and to anormally closed contact I of that relay. The connector 216 has aterminal 3 which is connected to a normally closed contact G and to anormally open contact H of the relay 220. The relay 220 has an armatureF associated with the contacts E and G and which is connected to theother terminal of the primary of the transformer 214, as mentionedabove. The relay 220 also has an armature I which is associated with thecontacts I and H, and this latter armature is connected to the terminal1 of the connector 216. The connector 216 serves to connect the housing52 of Figures 1 and 3 with the actuator housing 10 in those figures. Theterminals 1 and 2 of connector 216 connect with the running winding ofthe motor 12, and the terminals 3 and 4 connect with the startingwinding of the motor.

The terminal 5 of the connector strip 216 connects with the armature ofthe microswitch 100, and this armature is normally closed with a fixedcontact which, in turn, is connected to the terminal 8 of the connector.The terminal 6 of the connector strip is connected to a normally closedcontact of the microswitch 104, and the armature of microswitch 104 isalso connected to the terminal 8 of the connector strip 216. Themicroswitch 104 also has a normally open contact which is connected tothe terminal 7 of the connector strip 216. The terminal 9 of theconnector strip 216 is connected to the armature of the microswitch 102,and switch 102 has a normally closed contact which is connected to theterminal 10.

a It will be observed as the description proceeds, that themicroswitches and 104 are used not only to sense an obstruction in thepath of the door as it is opened and closed, but also to serve asreversing switches when the door reaches its fully opened condition orits fully closed condition. Under the latter circumstances, when thedoor reaches either one of its limiting conditions, the actuation of themicroswitches 100 or 104 conditions the circuitry so that the next timeit is operated, it will actuate the door for movement in an oppositedirection from the previous actuation.

Assume now that garage door is closed. When .the

tact. Now, under these conditions, the motor reversing.

relay 220 is not energized because the armature of the microswitch 104does not contact the lower contact. The relay 213 also is not energizedbecause an energizing circuit to its coil has not been made.

Assume now that a signal is received to operate the relay 202, or thateither the push-button 208 or 210 has been operated, also assume thatthe over-ride microswitch-102 is closed. When such switches or relaysare operated, an energizing circuit to the relay 218 is completed fromthe secondary of the transformer 214 so that the primary control relay218 is energized. A holding circuit for the relay is established throughits contacts B and A, through the resistor 207, and through the normallyclosed contact of the microswitch 10.4. The contacts D and C of therelay 218 now close so that terminal 1 of the connector 216 is connectedto one side of the primary of the transformer 214 and terminal 2 of theconnector strip is connected to the other side to energize the runningwinding of the motor 12. This also connects the terminal 4 of theconnector strip 216 to the same side of the primary as the terminal 1 oftheconnector, and the terminal 3 of the connector is connected to theother side of the primary. These connections supply electrical currentto the motor 12 in a manner tocause the motor to turn in a direction sothat the garage doon may be opened.

Itwill be noted that the relay 220 does not switch currents to themotor, since it is previously established in its de-energized conditionbefore the control relay 218 is. energized. This also applies on thereverse operation where the relay 220 is energized after current isremoved from the motor by action of the relay 218, which is caused to befaster than the pull in of relay 220 by resistor 207.

Assume that the door starts its upward movement under the control of theoperating mechanism described previously. The switch 100 now closes withits upper contact to provide an auxiliary energizing circuit to the coilof the relay 218 through its hold contacts B and A andthrough the upperfixed contact of the microswitch 104; This permits the door to continueits upward motion, even after the contacts of the relay 202 have beenopened, or after the push-buttons 2% or 210 have been released. Assumenow that the door meets with an obstruction on its upward motion. Suchan obstruction causes the sequence of mechanical operations describedpreviously, which move the armature of the switch 104 from its topcontact to its lower contact in Figure 8. This immediately breaks theenergizing current to the relay 218 and the door stops. The door is heldstopped with the armature of the switch Hi4 engaging its lower contactso that the motor reversing relay 220 is now energized. The next timethat the push-buttons 208 or 210, or the relay 2122 is closed, theaction is reversed with relay 223 latched in an energized position.until unlatched by opening of the holding circuit through switch 100when the door meets an obstruction or the downward limiting position.

The microswitch 1 .94 also can be used when the obstruction met by thedoor is the stop which is intended to limit its upward motion. Such alimit to the upward motion of the door causes the switch liM to beactuated so'that the door mechanism is in a condition to close the doorthe next time the relay contacts 202 are closed, or the next time thepush-button switches 208 or 210 are actuated. The lamp 54 is alsoilluminated by energiza tion of the relay 226.

In like manner, when the door reaches its lowermost position, or meetsan obstruction on the way down, the switch 100 opens to immediatelyd'e-energize the control relay 213 and to reverse the condition of thereversing relay- 220 at a discrete time displacement. This lettermicroswitch also serves not only as a safety feature in the event thatan obstruction is met, but also serves as a' limiting switch for whenthe door is fully closed.

It should be again noted that whenever the mechanism is de-energized,the door is positively locked at whatever position it is in when thede-activation of the mechanism occurs. The lead screw 24 provides apositive lock against any movement of the door until the lead screwagain is rotated. This, as mentioned above, not only provides a safetyfeature in which the door is immediately stopped upon meeting an object,but also provides a burglar-proof arrangement by which the door cannotbe opened when it is in a closed condition.

Upon failure of the equipment to operate on the down position when anobstruction is met which should' normally open the switch 100, theover-ride switch. 102 then operates, as discussed above, and this opensthe circuit to the primary control relay 218. The circuit cannot be.closed until a manual means is resorted to to move.

the door away from the jammed condition so that normal operation can berestored. This provides a safety feature, as explained, in which themechanism of the door is held in a condition in which it cannot beoperated until appropriate steps are taken to remove the fault and againto restore normal operation of the door.

The invention provides, therefore, a new and improved door operatingmechanism which is relatively inexpensive-in that it utilizes a minimumof component parts. Of paramount importance is the fact that the dooroperating mechanisrnof the invention is completely safe and includespositive means for immediately stopping the operation of the door shouldany object be encountered in the path of the door as it is being openedor closed. Also, the embodiment of the invention described aboveincludesv an over-riding feature which serves immediately to de-activatethe equipment upon a fault occurring in the control system. Themechanism of the invention is also advantageous in that the majorportion of the weight is concentrated in the actuator housing which maybe conveniently mounted on the header of the garage door so as topreclude the necessity for any additional bracing in the garage.

We claim:

1. An opening and closing mechanism for a garage door, and the like, thedoor being disposed in. a vertical plane when closed and supported to bemoved upwardly to a horizontal plane when opened, themechanisniineluding: a hanger assembly adapted to be mounted in aposition displaced rearwardly from the plane of the door in its closedposition and disposed substantially in the plane of the door in its openposition, ahousing adapted to be mounted in the plane of the door in itsclosed position and over the door, a drive motor supported on thehousing and including a drive shaft, a driven shaft rotatably supportedon the housing for limited axial movement and disposed in spacedparallel relationship with said drive shaft, an externally threadedelongated drive screw rotatably mounted at one end in said hangerassembly for limited axial movement with respect thereto, a resilientmember for coupling the driven shaft tothe other end of the drive screwto enable rotational'motion to be imparted to the drive screw throughthe driven shaft, the drive screw being supported by the hanger assemblyand by the resilient coupling member in a. position' extendingessentially perpendicular to the plane'of the door in its closedposition and in essentially axial alignment with the driven shaft, afirst pulley mounted in the housing on the drive shaft, a second pulleymounted in the housing on the driven shaft, a belt drive member in thehousing intercoupling the first and second pulleys for impartingrotational motion fromthe motor to the drive screw, a pair ofcompression coil springs positioned ment of the driven shaft against thecompression of at least one of said coil springs, a threaded yoke membermounted on the drive screw in threaded relationship therewith for axialmovement with respect to the drive screw upon rotation of the drivescrew, and a linkage arm having one of its ends pivotally fastened tothe yoke member and having its other end adapted to be pivotallyfastened to the top of the door to control the opening and closing ofthe door upon the axial movement of the yoke member and any obstructionto the movement of the door producing axial movement of the lead screwand of the driven shaft coupled thereto against the compression of oneor the other of said coil springs to actuate said electric switchingmeans.

2. The combination defined in claim 1 in which said linkage arm has aparticular V-shaped configuration to cause the forces exerted by thelinkage on the door in the opening of the door to be essentiallytangential to the arcs described by the top of the door during suchopening.

3. The combination defined in claim 1 and which includes a pair ofbearings mounted on the housing to support the driven shaft, a firstpair of thrust bushings mounted on opposite sides of the second pulleyin coaxial relationship with the driven shaft, 21 second pair of thrustbushings mounted on respective ones of the bearings in coaxialrelationship with the driven shaft and spaced from corresponding ones ofthe bushings of the first pair, said bushings serving as a support forsaid coil springs and providing bearing surfaces for the springs andsaid bushings further serving to limit the axial movement of said drivenshaft with respect to the housmg.

4. The combination defined in claim 1 in which said switching meansincludes a first electric switch and a second electric switch mounted onthe housing, said first switch having an actuating arm positioned to beoperated by said second pulley upon the axial movement of the drivenshaft in a first direction with respect to the housing, and the secondswitch having an actuating arm positioned to be operated by said secondpulley upon the axial movement of the driven shaft in a second directionwith respect to the housing.

5. The combination defined in claim 1 in which said switching meansincludes a first electric switch and a second electric switch mounted onthe housing, said first switch having an actuating arm positioned to beoperated by said second pulley upon the axial movement of the drivenshaft in a first direction with respect to the housing to a particularposition due to the door meeting an {obstruction during its closingoperation, said second switch having an actuating arm positioned to beoperated by said second pulley upon the axial movement of the drivenshaft in the opposite direction with respect to the housing and due tothe door meeting an obstruction during its opening operation, andswitching means including a third electric switch mounted on the housingand having an actuating arm adapted to be operated by said pulley uponthe axial movement of said driven shaft in said first direction beyondsaid particular position.

References Cited in the file of this patent UNITED STATES PATENTS2,253,170 Dunham Aug. 19, 1941 2,533,116 Jenkins Dec. 5, 1950 2,572,785Vaughn Oct. 23, 1951 2,637,550 Ritter May 5, 1953 2,676,294 Wilcox Apr.20, 1954 2,753,179 Hahn July 3, 1956 2,805,059 Green Sept. 3, 1957

